One of the desirable characteristics of a modern state of the art stereo system is the ability to create a sense of the listener being at the actual musical performance. A major factor in this is the degree to which the amience, i.e., the natural reverberation or echos of the recording hall where the music was played and recorded, can be heard. It is obvious that it would be desirable to eliminate the reflections produced within the listener's room, as such reflections mix with and confuse those in the recording. These listening room reflections reach the listener from a different direction than the direct sound from a loudspeaker, and thus, they also confuse the image placement in the soundfield. Many listeners, and advanced hi fi buffs in particular, have installed sound absorptive damping foam, made specifically for this purpose, on their listening room walls to eliminate reflections and achieve more natural sound. As is discussed in more detail below, the present invention uses foam or other acoustic absorptive material directly as an integral part of the loudspeaker system to acieve this purpose even more effectively.
It is important to distinguish the present invention from prior art loudspeaker systems wherein sound damping foam or the like is located within the speaker housing. Examples of such systems are disclosed, for instance in U.S. Pat. Nos. 4,161,995 (Pohlmann et al); 4,881,850 (Bonn); 3,512,605 (McCorkel); 3,720,285 (Russell et al) 4,286,688 (O'Malley); 3,944,020 (Brown); 3,982,607 (Evans); and 4,051,689 (Stallings, Jr.). Systems of this type are designed to absorb sound produced within the loudspeaker housing and obviously do not have any effect on sound coming from the front of the speaker, and clearly do not provide the advantages of the present invention discussed above, and below.